Tripod and target assembly



Feb. 12, 1963 M. H. HACKNEY 3,077,035

TRIPOD AND TARGET ASSEMBLY Filed Feb. 1. 1961 00 00743" Fig.2

MI/ard H. Hackney 1N VEN TOR.

3,li77,035 TRIPOD AND TARGET ASSEMBLY Milard ll. Hackney, EKG. Box 189, Longview, Tex. Filed Feb. it, 1961, Ser. No. 86,499 6 Claims. (Cl. 33-74) This invention relates to a sighting tripod for range poles or other sighting target devices and in general constitutes an improvement in the field of surveying.

A primary object of this invention therefore, is to provide a tripod support for range poles utilized for surveying purposes which embodies a novel feature by virtue of which a significant change in surveying procedures as heretofore necessarily practiced, reduces the surveying personnel required, surveying time and also increases the accuracy with which a survey may be made.

An additional object of this invention is to provide an economical means of taking advantage of the present trendtoward greater precision of angular graduation of surveying instruments, and sighting optics. For example, many of the presently produced surveying instruments, i.e., transits and/ or theodolites, give angular graduations of twenty seconds of arc; and others that are more expensive, give direct graduations of one second of arc. To obtain maximum benefits of these precision instruments, it is necessary that a precise sighting target device he used as a component part of the equipment. This invention provides at minimum cost, the necessary component part of the equipment, or the complement to the precision instrument. In the instance of transit and/or theodolite work, by means of this invention it is possible after quickly plumbing a range pole on a point to have the range pole held firmly in the plumbed position. By actual tests it is found that the average time required for plumbing a range pole on a point with this invention is one minute, or less.

The advantage of the range pole being held firmly in the plumbed, or vertical position, is that a sight taken on the top of the range pole is the same as if the sight had been taken on the point over which the range pole has been plumbed. Therefore, the use of this invention assures that sights taken at any point on a range pole will be the same as if the sights had been taken on the point on which the range pole is plumbed; and that projection of straight, or tangent lines, or horizontal angles turned from such sights are from the true line.

It is not possible for human hands to hold a range pole, or other sighting target device, in the true plumbed, or vertical position more than momentarily, without the aid of a brace, or support of some kind. This invention provides a firm constant support (stable equilibrium) for a range pole or other sighting target device, with minimum expenditure of time; and does not require further attention after being set in the required position.

Other sighting target devices, comparable in scope, commonly called sighting tripods, heretofore and presently used, have metal ball-in-socket heads for holding a range pole or other sighting device. These devices are heavy, take much more time to erect overa point, and are far more expensive in cost. The metal holder for range pole or other sighting device on such equipment, is damaging to the paint or external surface on a range pole or other sighting device.

This invention equipped with tripod legs, for transit and/ or theodolite work, weighs two to three pounds; and

3,77fi35 Patented Feb. 12, 1983 is therefore no burden to the user. In field use, this invention may be carried without removing the range pole therefrom, or if desired the range pole may be removed with ease. Therefore this invention is a distinct improvement in the field of surveying and/or engineering layout work.

In accordance with the foregoing objects, this invention features a head for a supporting tripod, to which tripod legs are pivotally connected for anchoring the device to the ground or other surface on which it may be used. A grommet of resilient material is disposed within the tripod head for frictio-nally receiving therethrough a range pole, or other elongated sighting target device. The grommet is so designed in relation to the tripod head, that a range pole may be placed therein, or removed therefrom, without damage to the painted surface of the range pole, the grommet of resilient material acts as a universal joint, or ball-in-socket connection, to the extent that it allows the tripod head to be canted in any direction necessary, without moving the range pole or other sighting target device from the plumbed position.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had "to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and to which:

FIGURE 1 is a perspective view of a plumbed range pole supported by the tripod device of the present invention;

FIGURE 2 is a perspective disassembly view of the tripod head.

FIGURE 3 is a sectional view through the tripod head.

FIGURE 4 is a partial sectional view taken through a plane indicated by section line 4-4 in FIGURE 1.

FiGURE 5 is a diagrammatic top plan view of a line sighting, illustrating the error avoided by use of the present invention.

FIGURE 6 is a diagrammatic side elevational, or profile view corresponding to the top plan View diagram of FIGURE 5. i i 1 Referring now to the drawing in detail, and inparticw lar to FIGURES 5 and 6, the particular problem in surveying, and/or engineering layout work to which the present'inventio-n relates will become apparent. FIG- URES 5 and 6 relate therefore to the establishing of a straight, or direct line from a point on a range pole 16 through a point 10 to an established point 12, by the use of a transit or theodolite located at point 10, using the method or procedure heretofore and presently used, i.e., by a person trying to hold the range pole 16 in the vertical, or plumb, position on the ground at point 18. In the illustration depicted by FIGURES 5 and 6, the range pole is considered as being eight feet in length, the length of the average range pole heretofore and presently in common use. In this illustration the range pole is considered as being out of plumb only one-half inch at the top of the range pole, an error not often noticeable by the person at the instrument (transit or theodolite) at a distance of three hundred feet. The sight is taken at the mid-point of the range pole, point 14, i.e., at a point four feet above the point 18, which reduces the actual error of sight by one-half, that is one-quarter of an inch. The line of sight is then projected toward point 12, which is twelve hundred feet from point lb, thus introducing an error in the line at point 12, of one inch, which is equivalent to an angle of 0O14.3 at point 1d. The significance of the present invention is therefore apparent, since by its use the range pole would have been supported on and quickly plumbed exactly on point 13, by any conventional method utilizing for example a plumb-bob cord, construction level or rod level or by sightings from the instruments being used in connection with the range pole, and although the sight was taken at point 14, not at point 18, the true line would have been then projected to point 12, by line 20, the true line sought.

It will be further apparent, that the turning of any horizontal angles from the line of sight points lid-18 will be in error with respect to the true line 28, by the amount of 00O0'14.3", as indicated in FIG RE 5.

Of particular significance in relation to the present invention is the fact that it is adaptable to any and all kinds of work pertaining to surveying and/or engineering layout, whereas prior supporting or sighting devices are not. Comparable supporting or sighting target devices heretofore used are of heavy construction, not easy to transport from point to point, take too much time to set up, and are too costly for economical use.

Not only may the projection of straight, or tangent, lines be established more accurately, and more rapidly as hereinbefore indicated, but the present invention is particularly beneficial for work Where it is required that many horizontal angles be turned from the same line. This would apply to general mapping work for example, and assures that all angles are taken from the identical line. Furthermore, two range poles supported by the present invention enables one man to do a far better angular traverse job than is ordinarily accomplished by a four man party. Similar savings in time and labor may be effected in various other surveying and/or engineering layout jobs.

Referring now to FIGURES 1 through 4, it will be observed that the range pole to which is illustrated in FIG- URE l as plumbed on the mark or track 22, is nonpendulously supported in said plumbed position by the tripod head device generally referred to by reference numeral 26 mounted on the tripod device generally referred to by the numeral 24. In the illustration the tripod head device is in a canted or angularly adjusted position with respect to the range pole by virtue of the uneveness of the ground, or other surface. The tripod device 24 also includes therefore three tripod legs 28 which are equally spaced from each other and pivotally connected to the tripod head 26 for support thereof with respect to the ground, or other surface.

The tripod head device 26 includes a casting member 39 to which the angularly spaced pivot ears 32 are connected and radially extend therefrom for pivotal connection to the tripod legs 28. The casting member 3d has a bore 34 therewithin which tapers or converges downwardly as more clearly seen in FIGURE 3. The tapered bore 34 accommodates therefore the resilient grommet member 36 which constitutes one of the most important features of the present invention.

The grommet 36 is made of any suitable resilient material, such as rubber or plastic, and includes a constant diameter bore 38 which is dimensioned for frictio-nally receiving therewithin a range pole 16, or other sighting device. The grommet 36 includes a downwardly tapering outer surface 40 to fit the tapering bore 32 of member 30. The grommet 36 may be secured to casting member 353 by either cementing, or by a snap fit. The latter method of securing the grommet 36 to casting member 30 facilitates the exchanging of grommets for different diameter range poles, or other sighting devices. It will also be observed that the tapered portion td of the grommet extends below the tripod head assembly. The grommet also includes an upwardly tapering portion 42 which extends above the tripod head assembly 26. It will also be observed that the lower end of portion 46 of the grommet 36 has an annular rib 41 disposed below'the member 30 providing a snap fit assembly of the grommet 36 with the casting member 30 of the tripod head assembly.

It will therefore be apparent from FIGURE 4, that the tripod head assembly 26 may be angularly adjusted with respect to the range pole 16 with the grommet so accommodating the range pole, or other sighting target device, and acting as a non-pendulous universal joint connection to the range pole, insofar as adjustability is concerned, for such purpose. The grommet 36 however will also frictionally grip the range pole for holding it in any angularly adjusted position without damage to the painted surface thereof. Also the range pole may be easily disassembled and assembled within the tripod head assembly by virtue of the grommet and adjusted with respect thereto. This enables plumbing of the range pole on the mark without interference for subsequent anchoring thereof in said plumb position by the tripod legs in the firm, constant manner aforementioned while holding the head assembly in some angularly adjusted position with respect to the range pole. Anchoring ofthe lower end of the range pole when supported in a plumbed position on the mark 22 will insure stable equilibrium when the tripod head is in a canted position. The range pole may then be able to withstand substantial displacing moments imposed thereon.

The foregoing is considered as illustrative only of the principles of the present invention. Further since numerous modifications and changes will readily occur to those skilled in the field wherein the present invention is useful, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. In combination with a sighting target device having an elongated rod portion assembly comprising, a support head, resilient means secured within said head and frictionally receiving said elongated rod portion to firmly hold said elongated rod portion in longitudinally adjusted position with respect to the supporting assembly and equally spaced leg means pivotally connected to the head for anchoring the supporting assembly in the ground after the sighting device has been plumbed on line at a desired point on which the target device is anchored.

2. The combination of claim 1, wherein said support head comprises an annular member having a downwardly converging bore within which the resilient means is fitted, and a plurality of equally spaced ears radially projecting therefrom for pivotal connection to the leg means.

3. The combination of claim 2, wherein said resilient means comprises a resilient grommet having a downwardly tapering portion disposed within the head and projecting therebelow, an upwardly tapering portion projccting above the head at a constant diameter bore for frictionally receiving the elongated rod portion of the sighting target device.

4. The combination of claim 1, wherein said resilient means comprises a resilient grommet having a downwardly tapering portion disposed within the head and projecting therebclow, an upwardly tapering portion pro jecting above the head and a constant diameter bore for frictionally receiving the elongated rod portion of the sighting target device and an annular rib connected to a lower end of the downwardly tapering portion of the Igrorciiimet for snap fit assembly of the grommet in the tea 5. In combination with a support head disposed in a tiltably adjustable plane, ground engaging support means operatively connected to the support head for fixedly supporting said support head in an adjustable plane spaced above the ground, a range pole extending through said support head in a vertically plumbed position in engagement with the ground at a predetermined location and elastically deformable friction means mounted in the support head and engaging the range pole for non-pendulous support thereof in said plumbed position.

6. In combination with an elongated target device, a supporting assembly comprising a support head, deformable means secured within said head for frictionally receiving and holding said elongated target device in longitudinally adjusted position relative to the support head, leg means operatively connected to said support head for anchoring the supporting assembly in the ground in spaced relation to said mark after plumbing of said tar- 10 get device with the support head being held in another adjusted position relative to the target device through the deformable means.

References Cited in the file of this patent UNITED STATES PATENTS Lafon Dec. 18, 1906 Robinson Aug. 15, 1939 Chaskin June 17, 1941 Zimmerman May 27, 1958 FOREIGN PATENTS Germany Sept. 18, 1891 France June 3, 1947 

1. IN COMBINATION WITH A SIGHTING TARGET DEVICE HAVING AN ELONGATED ROD PORTION ASSEMBLY COMPRISING, A SUPPORT HEAD, RESILIENT MEANS SECURED WITHIN SAID HEAD AND FRICTIONALLY RECEIVING SAID ELONGATED ROD PORTION TO FIRMLY HOLD SAID ELONGATED ROD PORTION IN LONGITUDINALLY ADJUSTED POSITION WITH RESPECT TO THE SUPPORTING ASSEMBLY AND EQUALLY SPACED LEG MEANS PIVOTALLY CONNECTED TO THE HEAD FOR ANCHORING THE SUPPORTING ASSEMBLY IN THE GROUND AFTER THE SIGHTING DEVICE HAS BEEN PLUMBED ON LINE AT A DESIRED POINT ON WHICH THE TARGET DEVICE IS ANCHORED. 